A more radical form of hypothecation has been proposed by the Liberal Democrats among others, in which taxpayers can declare a part of their tax to go to their choice of government functions. Obviously there has to be a limit to this (the LDs are suggesting 1% or so) or too many people would opt out of defence entirely in favour of popular causes like health, social security, and environment: though it might be interesting to see what changes happened if it was tried for a year or two. I am reminded me of the old slogan wishing for the day when the army had to hold fêtes and raffles to buy their missiles.